This study examines the benefits, commonality and outcomes of three green care approaches, to help raise awareness, understanding and value placed on these services by mental health commissioners, thereby helping to increase the number of projects commissioned. Although the three approaches of social and therapeutic horticulture (STH), care farming and environmental conservation as an intervention are contextually different, in practice the approaches often feature similar activities and have a similar ethos. The paper examines their scale across the UK and the current commissioning routes for green care to help inform potential new nature-based service providers. An estimated 8,400 people with mental health problems receive STH services per week and at least 5,865 service users on 173 care farms receive services for mental ill-health per week. Available anecdotal evidence suggests there is growing interest and demand for these services though overall referrals from clinical commissioning groups or from GPs for green care services remains patchy and relatively uncommon. As a consequence there is significant unused capacity across all three green care services. This research seeks to explore these issues and set out the steps required to enable a greater number of nature-based interventions to be commissioned in mental health care.